Wednesday, 16 May 2012

History of Electricity

History of Electricity

Starting With Mr. Edison andBen Franklin His LightMany people think Benjamin In 1879, Thomas EdisonFranklin discovered electricity focused on inventing awith his famous kite-flying practical light bulb, one thatexperiments in 1752, but would last a long time beforeelectricity was not discovered burning out. The problem wasall at once. At first, electricity finding a strong material forwas associated with light. the filament, the small wirePeople wanted a cheap inside the bulb that conductsand safe way to light their electricity. Finally, Edison usedhomes, and scientists thought ordinary cotton thread thatelectricity might be a way. had been soaked in carbon. This filament didn’t burn at all—it became incandescent; that is, it glowed.

Image courtesy of NOAA Photo LibraryThe BatteryLearning how to produceand use electricity was noteasy. For a long time therewas no dependable sourceof electricity for experiments.Finally, in 1800, AlessandroVolta, an Italian scientist, madea great discovery. He soakedpaper in salt water, placed zincand copper on opposite sidesof the paper, and watched thechemical reaction producean electric current. Volta hadcreated the first electric cell.By connecting many of these Alessandro Voltacells together, Volta was ableto “string a current” and createa battery. It is in honor of Volta that we measure battery powerin volts. Finally, a safe and dependable source of electricity wasavailable, making it easy for scientists to study electricity.

A Current BeganAn English scientist, Michael Faraday, was the first one to realize thatan electric current could be produced by passing a magnet througha copper wire. It was an amazing discovery. Almost all the electricitywe use today is made with magnets and coils of copper wire in giantpower plants.Both the electric generator and electric motor are based on thisprinciple. A generator converts motion energy into electricity. Amotor converts electrical energy into motion energy.42 Image courtesy of U.S. Library of CongressThomas Edison in his lab in 1901.The next challenge was developing an electrical system that couldprovide people with a practical source of energy to power these newlights. Edison wanted a way to make electricity both practical andinexpensive. He designed and built the first electric power plant thatwas able to produce electricity and carry it to people’s homes.Edison’s Pearl Street Power Station started up its generator onSeptember 4, 1882, in New York City. About 85 customers in lowerManhattan received enough power to light 5,000 lamps. Hiscustomers paid a lot for their electricity, though. In today’s dollars,the electricity cost $5.00 per kilowatt-hour! Today, electricity costsabout 12 cents per kilowatt-hour for residential customers, andabout 7 cents per kilowatt-hour for industry.

AC or DC?The turning point of the electric age came a few years later withthe development of AC (alternating current) power systems. Withalternating current, power plants could transport electricity muchfarther than before. In 1895, George Westinghouse opened the firstmajor power plant at Niagara Falls using alternating current. WhileEdison’s DC (direct current) plant could only transport electricitywithin one square mile of his Pearl Street Power Station, the NiagaraFalls plant was able to transport electricity more than 200 miles!Electricity didn’t have an easy beginning. Many people werethrilled with all the new inventions, but some people were afraidof electricity and wary of bringing it into their homes. Many socialcritics of the day saw electricity as an end to a simpler, less hectic wayof life. Poets commented that electric lights were less romantic thangas lights. Perhaps they were right, but the new electric age couldnot be dimmed.In 1920, only two percent of the energy in the U. S. was used to makeelectricity. Today, about 41 percent of all energy is used to makeelectricity. As our use of technology grows, that figure will continueto rise.